LAUSR

Funding information National Science Foundation, Grant/Award Number: 1502755 Abstract This study is focused on engineering for sustainable communities (EfSC) in three middle school classrooms. Three in‐depth case studies are presented that explore how two related EfSC epistemic toolsets—(a) community engineering and ethnography tools for defining problems, and (b) integrating perspectives in design specification and optimization through iterative design sketch‐up and prototyping—work to support the following: (a) Students' recruitment of multiple epistemologies; (b) Navigation of multiple epistemologies; and (c) students' onto‐epistemological developments in engineering. Using a theoretical framework grounded in justice‐oriented notions of equity intersecting with multiple epistemologies, we investigated the impact of the related epistemic toolsets on students' engineering engagement. Specifically, the study focused on how the tools worked when they were taken up in particular ways by teacher and students, and how the nature of their iterative engagement with the tools led to outcomes in ways that were equitable and consequential, both to students' engineering experiences and their engineering onto‐epistemological developments, and also in responding to the community injustices prototypes were designed to address. Tensions that emerged are discussed with further reflection on what the EfSC epistemic toolsets suggest about the affordances of a productive epistemic space and the concomitant risks related to larger institutional norms,